1. Field of the Invention
The present invention relates to a tool for removing the protecting and insulating covering or coverings of a coaxial cable used in telecommunication or power supply for purpose of connecting to a coaxial cable connector.
2. Prior Art Statement
For removing an outer insulating covering of a coaxial cable in order to connect the coaxial cable to a coaxial cable connector, such as disclosed in Japanese Patent Application Opened Publication No. 62-271,381, it has been a common practice to use a cutter knife in the field. At first a cut is made in the outer protection and insulation covering both in circumferential and axial directions. Then, the covering is peeled off by hand. Also, a particular peeling tool for the removal of covering has been used.
A particular peeling tool for this purpose has the shape of a spanner having two jaws. One jaw of which is fixed and provided with a pair of rollers. The other jaw is arranged movable and provided with a cutter roller. At use, a portion of an outer insulation covering of a coaxial cable is placed between the pair of rollers of the fixed jaw. The movable jaw is moved forward against the fixed jaw so as to push the cutter roller to cut-in at one point of the outer insulation covering of the coaxial cable. Then by rotating the spanner shape tool about the coaxial cable circumferential cut is made in the outer insulation covering so that it can be peeled off. Thereafter, the peeled off portion is removed by using cutting pliers and a nipper or like tool.
However, by using such a conventional cutter knife or peeling tool, it has been very difficult to cut off only the outer insulation covering without damaging the outer conductor of the coaxial cable. More especially, in case of a coaxial cable for CATV purpose, which has the outer conductor made of aluminium pipe, if the pipe is damaged even by a very small cut in the circumferential direction on the aluminium pipe, it easily tends to break by light bending. When it is broken, the transmission characteristics will greatly deteriorate and also might cause trouble in waterproofing.
In cutters for use in outer insulation covering of rubber or like soft materials, the blade of the cutter can very soon be spoiled so that frequent interchange of the cutter blade is required. In case of a cutter knife, a supply of cheap cutter blades is rather easy to obtain and use. However, in case of a particularly designed cutter tool, the tool itself is expensive and the supply of the particular cutter blade is not simple. Thus it has a great disadvantage of high and continuous cost.
Furthermore, for connecting a coaxial cable to a coaxial cable connector, it is necessary to expose a core wire or a central conductor over a predetermined length and to expose the outer conductor over a predetermined length from the base of the exposed central conductor. Thus work is necessary to mark a point on the outer insulation covering by measuring the required length and thereafter the covering is cut from the marked point.